This is terrible. I don't know why these things happen. My mind just can't grasp it at all. I see people trying to compare one horror with another, as if that makes all of them more comprehensible, brings them into the range of ordinary human behavior. I understand the desire.

There's a craft of responding to this kind of horror. Treating the severely injured. Gathering the survivors -- comforting the shocked and frightened, bringing family members together, making the transition from terror to grief. I don't know if the responders are really *better* now than they were after Montreal or Columbine but they have a standard practice. They drill. There is enough expectation of these things that they have drills for it. Such a world we live in.